1. Technical Field
The present invention relates to a data generating system and a method to be used in a motor vehicle, here denominated host vehicle, for generating distance data as to the prevailing distance between the host vehicle and an object travelling in the predicted path of the host vehicle and velocity data as to the prevailing velocity of said object. The invention also relates to an adaptive cruise control system comprising such a data generating system. Furthermore, the invention relates to a computer program comprising computer program code for implementing the method, a computer program product comprising a data storage medium readable by an electronic control unit and having said computer program stored thereon, and an electronic control unit.
2. Background Art
An adaptive cruise control system for use in motor vehicles is previously known, e.g. from US 2003/0204298 A1. The motor vehicle provided with the adaptive cruise control system is in the following referred to as the “host vehicle”. Under driving conditions with no other vehicle within a certain range in front of the host vehicle in the predicted travelling path thereof, the adaptive cruise control system, when activated by the vehicle driver, influences the operation of the host vehicle so as to keep the velocity of the host vehicle essentially equal to a desired vehicle velocity set by the driver, in the following referred to as the “set vehicle velocity”. Under said driving conditions, the adaptive cruise control system operates in a conventional cruise control mode. When an obstructing object, such as another motor vehicle, travelling in the predicted path of the host vehicle at a velocity lower than the set vehicle velocity of the host vehicle is detected within the above-indicated range, the adaptive cruise control system reduces the velocity of the host vehicle and makes the host vehicle follow the detected object at a desired distance from it, i.e. the adaptive cruise control system will in this case influence the operation of the host vehicle so as to keep the host vehicle at a desired distance from the detected object. A detected object travelling in the predicted path of the host vehicle is in the following referred to as “target object” and said desired distance is in the following referred to as the “set distance”. When the obstructing target object is accelerated to a velocity above the set vehicle velocity of the host vehicle or when it for any reason no longer is detectable in the predicted travelling path of the host vehicle and no other obstructing target object is detected, the adaptive cruise control system resumes the cruise control mode and accelerates the host vehicle back to the set vehicle velocity.
When a detected target object runs out of the field of view of the object detecting means included in a conventional adaptive cruise control system due to a sharp road curve, the adaptive cruise control system will accelerate the host vehicle back to the set vehicle velocity. Hereby, the host vehicle might get undesirably close to the target object and it might be necessary for the driver of the host vehicle to manually activate the breaks of the host vehicle, which will deactivate the adaptive cruise control system. There is also a risk of a dangerous accident in a situation of this type due to the undesired acceleration of the host vehicle. A solution to the problem of undesired acceleration of the host vehicle in this type of situation is disclosed in US 2003/0204298 A1. According to this solution, a resumption of the cruise control mode is inhibited and the prevailing velocity of the host vehicle is maintained when a previously detected target object is no longer detectable at the same time as it is established that the host vehicle is travelling in a curve.